Broadband X-Ray Diagnostics of a Relativistic Laser Plasma

Absolute measurements of the X-ray spectrum of a plasma formed by intense femtosecond laser radiation on the surface of a solid target in a wide range of interaction parameters with varying the intensity and contrast of a laser pulse have been carried out. The energy distribution of the photon flux from the plasma created on the metal target in the range from 0.1 keV to 1 MeV and higher has been determined for the first time in a single experiment. Using the data obtained, physical processes in the interaction region have been analyzed. The temperatures of background and hot plasma electrons have been estimated. The role of these electron in the generation of the photon flux and the efficiency of laser radiation conversion into various ranges has been studied. A close relationship between the observed results and the contrast and peak intensity of laser radiation has been found.